Week 8: Selective Realism
Notes General '''Realism vs. Antirealism''' The realism debate happens on 3 axes. It is an ontological (Is there a mind-independent world?), an epistemic (Can we know anything about this world?) and a semantic (Can we say true things about this world?) debate. It is usually about the unobservables. Realists say that there are unobservables, we can know things about them and we can say true things about them. '''Logical positivists''' Logical positivists believed that only observation statements are meaningful, so anything about unobservables would be meaningless. It is not just that sentences about unobservables may be wrong, it is that we cannot even formulate meaningful sentences about them, so we could never say true things about them. '''Constructive empiricism (CE)''' According to Van Fraassen and constructive empiricists, science should aim to formulate true sentences only about observables but posit empirically adequate claims and not true claims about unobservables. Empirically adequate means that it conforms to our observation. CE is agnostic about the ontology of unobservables and acceptance of a theory consists of believing in its empirical adequacy rather than its truth. CE may be the most sensible form of antirealism, but the empirical success of science needs some explanation, hence NMA. '''The No Miracles Argument (NMA)''' the no miracles argument put forth by Putnam is an argument that says there are no miracles, and it is not a cosmic coincidence that our observations confirm the results of our science. It is not a coincidence on a cosmic scale, that science gets things right. It gets things right, because the world is the way science describes it So science must say true things about unobservables, those unobservables must exist, and we are able to gain knowledge about them. '''Pessimistic Meta Induction (PMI)''' The PMI states that we should not believe that we will ever refer to unobservables/make true statements about the world, given our past failure to do so. In the history of science, it always turned out that our theories are not making true claims about the world, it would be rather crazy to think that it will, in the future. While there may be things in the unobservable realm, it is certainly impossible to make true claims about them or to know anything about them. We would also never know if we did. '''Structural Realism (SR)''' So realists should find something that survives theory change, some claim that has been made by science and is not refuted by new observations. SR states that it is the structure of the world that we were able to say true things about. It is the structure, so the relations between unobservable, that we got right. Certain equations in a theory describe these relations, that may get new interpretation, but the equation itself survive theory change. An example that has been used many times by SR is the Fresnel's wave equation for light. Fresnel thought that light was going through ether, a medium that transports the wave. However when it turned out that ether does not exist, light behaved according to Fresnel's equation, and it get a new interpretation; light still being wave like without a medium. '''Types of SR''' There are two main branch of structural realism: Epistemic and Ontic. Epistemic SR claims that the only thing science is able to say true things about unobservables are structures, the relations between unobservables, while being agnostic about the existence of unobservables. Ontic SR claims that unobservables do not exist, only the relations among them do. That is relations without relata. = '''Epistemic Structural Realism (ESR)''' = There are two main branch of ESR: '''Lecture''' '''NMA''' “The positive argument for realism is that it is the only philosophy that doesn’t make the success of science a miracle” (Putnam 1979: 73) [emphasis added]. argument can be directed at both science or theory The truth (or approx. truth) of theory T is the only view that that doesn’t make the success of T a miracle. The NMA can also be formulated as an explanation. Explanationism: The only (or best) explanation of a theory’s success that does not render it miraculous is that the theory is true or at least approximately true. '''Success''' Predictive/empirical: theory's consequences (predictions/accommodations) come out true Explanatory: theory provides understanding vis-á-vis some domain of inquiry Novel: ability to predict novel phenomena '''Inference to the Best Explanation (IBE)''' NMA as explanation is an istance of IBE: Abductive argument IBE: preference for the hypothesis that best explains the available evidence: step from premises to conclusion = ampliative '''Example 1''' 1. Two friends had an argument, parted ways 2. Someone saw them jogging together Best explanation: Two made up and are enjoying a run together. Other explanations: Two are fighting it out while running '''Example 2''' Evidence: Light from a galaxy appears to exhibit a red-shift Best explanation: The galaxy is receding from us. Other explanations: Galaxy is stationary '''Constructive empiricism (CE)''' blocks NMA: IBE have no epistemic relevance, explanatory factors are at best pragmatically relevant. Simplicity: realists: guide to the truth, CE: good because of ease of calculation The best of a bad lot: best explanation is not neceserily true or good. Reply: additional demand: not just the best, but the "one [that] is sufficiently good" (Lipton 2008, p.196) Counter-reply: How do we know if sufficiently good as opposed to merely the best available? '''Success and Truth''' Realists: if a theory T is successful it is true, but deduction is conservative (truth-preserving), so any consequence of T is also true. Complete success to truth principle: if a theory is true, it is completely successful. And if it is completely successful, then it is true. Degrees of success: complete success is too much partly true --> partly successful, partly successful --> partly true More successful: number of true consequences strictly greater (what about cases where no theory has such a strict advantage?) graded notions of truth: not all theories in 1 basket --> approximate truth verisimilitude (appearing to be true) and truthlike partial truth: estimated approximate truth, partial truth (no need to know how close it is to the truth, we can judge if it has some truth content or more truth content than another theory) Popper's (1963) approximate truth: if a theory has more true sentences than false ones. (problem: language plays a role in determining which hypotheses is closer to the truth) '''Pessimistic Meta-Induction''' Success to truth and to reference denied (inference from success to truth is obviously invalid, but is it reliable or inductively strong?) History : inductively supporting that our current/future theories will succumb just as our former ones. --> we should not believe in the approximate truth or in the successful reference of their terms. Laudan's list of discarded theories: caloric theory of heat, the electromagnetic aether, the optical aether, etc... ''pessimistic'': cannot claim that our best scientific theories are true ''inductive: ''ampliatively supported historical trend ''meta: ''not an induction in science but about it '''Theories of reference''' descriptivist theories: reference is fixed by virtue of a term's associated descriptions. Naive descriptivism: A term t refers to an entity e if and only if e satisfies all the descriptive claims associated with t (Frege, Russel, Searle) . --> too demanding (the naive version) reference is fixed via a term's causal history A term t refers to an entity e if and only if t was used to originally dub e (after some causal contact with it or samples of it) and any speaker’s subsequent use of t is causally linked back to the original dubbing. (Kripke, Putnam, Boyd) --> too liberal as anything is allowed to refer (oxygen as 'dephlogisticated air') Referential continuity: successor theories preserve successes of their predecessors and add to them - strictly closer to the truth - preserving parially true parts, preserve theor posits - referentially continuous with their predecessors -->problematic Basic reading This section should be objective. It would be nice to see summaries of the readings, this way we can interpret everything to ourselves and do not have to rely on other people's notes, without having to read every reading again. Further reading ☀Votsis, I. (2012) ‘The Prospective Stance in Realism’, ''Philosophy of Science'', vol. 78(5): 1223-1234. - Truth and empirical success - '''Edifice of realism erected – inference from empirical success to truth '''association between what we might call ‘the empirical success’ of a theory, on the one hand, and its truth content, on the other, is the pillar upon which modern scientific realism is erected. - From the 1960s onward, some of the most prominent attempts have been historically motivated. Kuhn, Feyerabend, Laudan, and various others have gleefully indicated that '''History of science is a scrapyard of empirically successful theories now deemed false''' . - in-principle existence of rival theories that are as empirically successful as the very theories we might hold at any point in history. Historical arguments can be thought of as special cases of the more general '''underdetermination arguments.''' Desired upshot: the same for advocates of both the historical and the underdetermination arguments, namely, to '''weaken the link between empirical success and truth content'''. - '''Truth/empirical success –-> Inference from Empirical Success to T is deductively invalid, so ES not sufficient '''à'''But is it reliable? '''à''''''The '''antirealists''' claim they are not, pointing to the scrap yard where one-time imperious theories lie rusting. In response, '''realists''': reliability of success-to-truth inferences can be upheld: scrap yards '''contain parts''' that before long are employed to outfit new theories. - '''Psillos – causal-descriptivist theory – reference = satisfying causal description''' ...............- '''''' 3 questions Answer all questions, this should be discussed in pairs at least, feel free to suggest changes or additions even after it has been uploaded. Question 1 Question 2 Question 3 Essays It would be nice to see essays taken apart, making the sections clear, or even to put suggestions here. This section does not have to be an essay, rather suggestions for arguments and parts for answering the question. Complete essays can be uploaded to the drive corresponding to the wiki. First essay Second essay=